Rotary ball mill



Dec. 12, 1939. E. G. SUNDFELT 2,183,156

ROTARY BALL MILL Filed April 9, 1938 '3 Sheets-Sheet 1 ea 67 68 6* p P66 47 I L J k I r l'l -58 j/' 32 "II-1:433 I. 1 l8 /5 n l 60 38 l 3 5 I: i i ll -/0 I? I8 3 f I 3 30 55 14 I 'I n I I h 54 52 .25 2a 34- 29 t Sit I INVENTOR. my 1 92341 6. Sandie Dec. 12, 1939- E. G. SUNDFELT ROTARY BALL MILL Fina A ril 9, 193B 3 Sheets-Sheet 2 A TORNEY Dec. 12, 1939.

E. G. SUNDFELT ROTARY BALL MILL Filed April 9, 1938 5 Sheets-Sheet 3 Patented Dec. 12, 1939 I 2,183,156 ROTARY BALL MILL Emil G. Sundfelt, Seattle, Wash.

Application April 9, 1938; Serial No. 201,123

' 4 Claims. (01. 83-45) This invention relates to a rotary ball mill for use in grinding or pulverizing hard material, such as mineral bearing rocks and ores which are supplied to the ball mill along with water.

A primary object of this invention is to provide a rotary ball mill for use in carrying out a wet grinding process, said ball mill having means for providing a continuous recirculation of coarser material around the balls of the mill until said coarser material is thoroughly ground and pulverized and said ball mill also providing for the self classification and removal of the more finely pulverized material.

Another object is to provide a rotary ball mill for wet grinding having a recirculation means for continuously recirculating coarse material around the balls until said coarse material is thoroughly ground and at the same time having a zone in which the Water is quiet and from which the finely ground material may be taken off.

In the dry grinding of rocks, ores and like material in ball mills and like machines, means have been provided for re-circulating the dry material but these means have been of such form as to produce agitation of the material and to provide fora separation of the finer from the coarser material by agitation and blowing action. The present-invention provides for re-circulation of wet material and at the same time maintains within themachine a quiet and non-turbulent zone where the ground material may be taken off.

Another object of the invention is to provide a ball mill having an upper grinding ring and a lower grinding ring between which grinding balls are operatively disposed, said upper grinding ring having'vanes operatively connected therewith in suitable positions to maintain a continuous recirculation of water and material which is being ground around the balls and between the two grinding rings when the upper grinding ring is rotated. y

The above mentioned general objects of my invention, together with others inherent in the same, are attained by the device illustrated in the following drawings, the same being a pre- Fig. l, and showing a rotor and other parts in plan; 'i Fig. 3' is a detached view of the rotor in elevation;

Fig. 4 is a bottom plan view of the rotor; Fig. 5 is a fragmentary sectional view of the rotor taken substantially on broken line '55 of Fig. 2; and I p Fig. 6 is a view similar to Fig. 2 showing a modified form of amalgamation plate.

The machine comprises a base portion Ill, supported on legs M, and having a cylindrical shell [2' welded or otherwise rigidly secured thereto. The shell 52 constitutes the side walls of a receptacle for the reception of water and material to be ground. A centrally positioned frame member I3 is secured by-screw means M to the base portion it.

I A lower grinding ring'l5 is supported within a conical seat it, provided forit in the base portion Ill. Preferably interfitting notch and lug means i'l are provided in the seat 16, and periphery of the ring l5, as shown at the left in Fig. 1, to

and resting on the balls l9. Enough balls I?! are provided so that they fill the two races and'are substantially in contact with each other, as shown in Fig. 2. Ample room for the circulation of water and material betweensaid balls is pro vided, due to the curvature of the balls. Also, the upper and lower ball raceslfi and 2! are spaced far enough apart to allow for a circulation. of water and material thereb'etween.

The upper grinding ring 28 is provided with' a hub portion 22, and a plurality of vanes 23" are provided between the hub portion 22 and the rim of said grinding ring. These vanes are pitched, as best shownin Fig. 5, so that they will scoop up the Water and material as the grinding ring 20 rotates and direct the same upwardly and out wardly. The result of this action of the vanes is that the water and material are circulatedaround and between the balls It, in the direction indicated by the arrows in Fig. l, to provide for the re-grinding of the material until it is com"- pletely pulverized. After the solid material has been reduced to a very finestate it will no longer re-circulate but will rise to the top of the'water and may be taken off by take-oil means hereinafter described.

The lower portion of the central frame member 13 is of inverted dish shape and is provided with a closure member 24, which has a central bear ing hub 25. The closure member 24 cooperates with the lower portion of the frame member it; to provide an oil tight gear receptacle 25, wherein a bevel gear 2? and a driving-pinion 28 may operate in a bath of oil. *A tubular shaftgZB ,is:

journaled in the bearing hub 25, and in a similar bearing hub 39 provided in central frame member IS. The bevel gear 2'! is keyed to this tubular shaft 29 by key means 3!. Preferably antifriction bushings 32, of bronze or like material, are provided in the bearing hubs 22 and 30 for the tubular shaft 29 and washers 33 of like material are provided at the location or" the ends of the hub of the bevel gear 21 and at the upper end of the hub 30. Preferably oil seal means 34 is provided at the lower end of the bearing hub 25.

A sleeve 35 fits over the upper end portion of the tubular shaft 29, and is connected with the said shaft by key or spline means 36, so that it is rotatable with said shaft 29. The lower end portion of this sleeve 35 has a disc shaped flange 31 thereon. The flange 3'! is provided with a downwardly projecting annular guard member 38, which extends over the upper end portion of the hub 30 and is of larger diameter than said hub 30, to leave between said hub 35 and said guard member 38 a space for the reception of packing means 39, by which the entrance of grit and water into the bearing structure is prevented. An upwardly projecting annular guard member 40 on the frame member l3, extends upwardly around the guard member 38 in spaced relation therefrom and terminates in slightly spaced relation from the flange 31. The peripheral portion of the flange 31 is curved downwardly over the upper end portion of the guard member 42. A water inlet pipe 4! is connected by a passageway 42, with the space within the upwardly projecting guard member 40. When the machine is in operation a constant supply of clean water is admitted through this water inlet pipe 4| and caused to flow upwardly and discharge radially outward through the narrow and restricted space between the flange 3'! and upwardly projecting guard member 40 to prevent any grit from gaining entrance to the bearings and to supply water as needed to the interior of the ball mill.

The hub 22 of the upper grinding ring 25 is preferably provided with an octagonal passageway 43, which fits over a correspondingly shaped portion 44 on the sleeve 35, whereby the upper grinding ring 20 will be rotated by rotation of the sleeve 35 and at the same time will be free to move up and down on the sleeve 35.

For the purpose of exerting a resilient downward pressure on the upper grinding ring 25, I provide a tubular sleeve 45, which rests on the upper end of the hub 22, and has a cap 46 in the upper end thereof. A rod 4'1, having nuts 48, on the upper end thereof extends downwardly through the cap 46 and through the tubular shaft 29. A disc 49 is provided on the lower end portion of the rod 41 and retained thereon by nuts 50. A compression spring 5! has one end portion supported on the disc 49 and the other end portion supported by a ball bearing 52, provided in the lower portion of the hub 25 of the closure member 24. The resilient force of the spring 5i is transmitted through the rod 41 and sleeve 45 and exerted as a downward pressure on the upper grinding ring 20.

The pinion 28 meshes with the bevel gear 2? and said pinion is secured to a shaft 53 which is journaled in a bearing 54 and may be driven by any suitable means not shown. The upper end portion of the hub 25 has an annular recess 55 for the purpose of catching oil which is splashed by the gears 21 and 28 and vane members 55 are secured to the bevel gear 2'! and positioned within the annular recess 55, so as to pick up oil and direct the same upwardly through holes 51 in the bevel gear 21, to insure ample lubrication for the bearing in the hub 30 of frame member l3. Suitable oil passageways are provided to insure proper lubrication of all bearings. The construction of this gear box and bearing means together with the provision of the packing 40 and the provision of means for introducing clean water around the bearing to keep out the grit makes it safe and practical to position the driving means for this machine below the machine without danger that said driving means will be damaged by grit from the machine.

Preferably an annular gutter 58 is provided in the upper portion of the base member Ill to catch precious metals and a draw-off conduit 59 connects with said gutter. Also preferably a mat 68, of suitable material to retain precious metals is provided in the bottom portion of the machine. Also amalgam plate means BI is preferably provided inside of the shell i2. An overflow or takeoff pipe 62 has an upwardly directed open end portion positioned above the upper end portion of the rod 47 substantially axially of the machine. This overflow pipe 52 extends outwardly through one side of the shell 12. Two coaxially positioned cylindrical bafile members 64 and 65 are adjustably supported in the upper portion of the shell l2 coaxially of said shell. The take-off opening 63 of the pipe 52 is positioned inside of the baffle member 64. The baflie member 64 is substantially smaller in diameter than the baffle member "55. The two bailie members are formed of perforated sheet metal and they serve to break up waves and ripples and currents and agitation in the water and insure substantially still water at the location of the take-off 63. This is desirable to prevent loss of values and said ballle members and 65 insure still water at the location of the take-off, even though the vanes 23 impart much turbulence to the water in the lower portion of the machine. may be adjustably supported by any suitable means, such as chains 56, which adjustably engage with bars 6! that extend across the top of the shell 52. The stillness of the water at the location of the take-oil opening 63 may be varied to a certain extent by vertically adjusting the bafiles 54 and 55 in the shell 22.

One or more chutes 68 for the inlet of solid matter may be provided at the upper end of the shell [2.

In Fig. 6 a modified form of amalgamation plate is shown. Here the plates 59 replace the plates 5! of the other figures. These plates 63 are vertically disposed and project inwardly. The values are scrubbed and cleaned by the action of the grinding balls l9, and while they are thus clean. they are thrown outwardly and by impact. contact the amalgamation plate 59. The action of the amalgamation plate is thus enhanced.

In the operation of this rotary ball mill. the shell 62 is filled with water up to substantially the level of the take-off 53. power is applied to the shaft 53 to rotate the upper grinding ring 25 and solid matter to be ground is introduced through the chutes 68. The solid matter settles to the bottom and passes between the balls 19 by which it is crushed and ground. The vanes 23 continuously scoop up the water and solid matter and direct the same upwardly and outwardly, thus keepin up a continuous circulation of the solid matter between the balls !9 and grinding rings !5 and 25 so that this solid matter is rapidly The baffle members 64 and 55 driven shaft,

and efiiciently ground. As this material is ground the lighter material, when finely pulverized, finds its way to the top of the water and is taken ofi through the pipe 52. The heavier material and precious metals remain in the lower portion of the machine or are caught by amalgam plate means 5 i. The action of the vanes 23 tends to throw the material out against this amalgam plate means, thereby bringing the values in contact with said amalgam plate means 8| or 539 and increasing the efliciency of the machine.

The driving means is positioned below the machine where it is out of the way and said driving means is adequately protected against damage by grit.

Obviously, changes may be made in the form, dimension and arrangement of theparts of my invention, without departing from the principle thereof, the above setting forth only a preferred form of embodiment.

I claim:

l. A device of the class described, comprising a cylindrical receptacle for water and solids to be ground; a lower grinding ring positioned substantially axially of said receptacle and providing the lower part of an annular ball race; an upper grinding ring positioned axially of said lower grinding ring and providing the upper part of an annular ball race; a plurality of grinding balls .disposed in the annular ball race between said two grinding rings; a driven shaft positioned axially of said grinding rings; a plurality of spaced apart vane members adapted to operate below the surface of the water and solids to be ground and extending above said grinding balls and connecting the upper grinding ring with said driven shaft, said vane members providing passageways for water and solids therethrough and said vane'members extending upwardly and outwardly urging the water and solids in a circular path which is upwardly and through the said passageways, thence outwardly toward the walls of the receptacle, whereby gravity separation occurs and the finely ground light solids will rise in the receptacle and coarser heavy solids will descend and move downwardly and between the grinding balls and the rings and will then be reground and pass upwardly and through the vanes as described; and take ofi means operatively positioned in the upper portion of the receptacle to remove the finely ground lighter rising solids.

2. A device of the class described, comprising a cylindrical receptacle for water and solids to be ground; a lower grinding ring positioned substantially axially of said receptacle and providing the-lower part of an annular ball race; an upper grinding ring positioned axially of said lower grinding ring and providing the upper part of an annular ball race; a plurality of grinding balls disposed in the annular ball race between said two grinding rings; a driven shaft positioned axially of said grinding rings; a plurality of spaced apart vane members adapted to operate below the surface of the water and solids, to be ground and extending above said grinding balls and connecting the upper grinding ring with said said vane members providing passageways for water and solids therethrough and said vane members extending upwardly and outwardly urging the water and solids in a circular path which is upwardly and through the said passageways, thence outwardly toward the walls of the receptacle, whereby gravity separation 00- curs and the finely ground light solids will rise in the receptacle and coarser heavy solids will descend and move downwardly and between the grinding balls and the rings and will then be reground and pass upwardly and through the vanes as described; bafile means disposed in the water and solids in the upper portion of said receptacle and removed from the circular path of the water and solids providing a non-agitated and quiet take-off area; and take off conduit means to water and finely ground light solids. 3. A device of the class described, comprising a cylindrical receptacle for water and solids to be ground; a lower grinding ring positioned substantially axially of said receptacle and providing the lower part of an annular ball race; an upper grinding ring positioned axially of said lower grinding ring and providing the upper part of an annular ball race; a plurality of grinding balls disposed in the annular ball race between said two grinding rings; a driven shaft positioned axially of said grinding rings; a plurality of spaced apart vane members adapted to operate below the surface of the water and solids to be ground and extending above said grinding balls and connecting the upper grinding ring with said driven shaft, said vane members providing passageways for water and solids therethrough and said vane members extending upwardly and outwardly urging the water and solids in a circular path which is upwardly and, through the said passageways, thence outwardly toward the walls of the receptacle, whereby gravity separation a cylindrical receptacle for water and solids to be ground; a lower grinding ring positioned substantially axially of said receptacle and providing the lower part of an annular ball race; v

an upper grinding ring positioned axially of said lower grinding ring and providing the upper part of an annular ball race; a plurality of grinding balls disposed in the annular ball race between said two grinding rings; a driven shaft positioned axially of said grinding rings; a plurality of spaced apart vane members adapted to operate below the surface of the water and solids to be ground and connecting the upper grinding ring with said driven shaft, said vane members providing passageways for water and solids therethrough and said vane members urging the water and solids to be ground in a circular path, which is between said grinding balls and said grinding rings and above said grinding balls, whereby gravity separation occurs and the finely ground light solids will rise in the receptacle and coarser heavy solids will descend and move downwardly and between the grinding balls .and the rings and will then be reground and recirculated as described; and take oil means operatively positioned in the upper portion of the receptacle to remove the finely ground lighter rising solids.

EMIL G. SUN'DFELT. 

